Dual-mechanism auxetic-core protective sandwich structure under blast loading

Abstract

This paper introduces a protective sandwich structure with simultaneous auxetic compression and tension behaviour (termed as the dual-mechanism) in the core. To achieve the proposed mechanism, a novel architected cellular structure, named as the dual-mechanism auxetic (DMA), was developed. The protective performance of the DMA was examined by subjecting the DMA-core sandwich panel (DMASP) to blast loading through computational modelling. A series of dynamic numerical models were developed in LS-DYNA, and validated with the past experimental results. The protective performance of the DMASP was evaluated comprehensively based on energy absorption, stress mitigation, and deflection control. Moreover, the protective performance of the DMASP was compared with an equivalent areal density solid plate. In addition, parametric studies were conducted to investigate effects of various design parameters and explosive environments on the protective efficacy of the DMASP. The numerical simulations uncovered that, in addition to high energy absorption capacity of the DMA core, the dual-mechanism was beneficial to mitigate high stress transfer to the protected structure by redirecting stress in the lateral direction through auxetic tensile behaviour. Furthermore, the DMASP offered better protective performance than the equivalent solid structure with respect to all the evaluation criteria under different blast loading scenarios.